Conical stabbing guide and clamp system for riser pipe installation

ABSTRACT

An apparatus and method are herein provided for installing a riser pipe on an offshore platform. A plurality of vertically aligned female cone members may be clamped along the length of the platform. A monorail may be secured to the riser pipe and aligned along the axis thereof. Mating male cone members may be slidably mounted on the monorail of the riser and roughly positioned for insertion into the female cones. A guide line may be fun from a surface winch through a dead man ring or sheave mounted on the platform beneath a female cone member and up through the cone member to connect with the lower end of the mating male cone member. The riser pipe may be supported by a surface crane and disposed with the lower end of each male cone positioned generally above a female cone. The riser pipe is lowered so that the male cones are partially inserted within the female cones. In this step, the guide line may be utilized as a positive control means of bringing the cones into alignment for proper mating engagement. After the cones are properly engaged, locking pins may be inserted through the lower portions of the male cones and a frictional connection between each male cone and the monorail released to slide the riser pipe downwardly to its final position. The riser pipe may be jetted into the water bed in the conventional manner. With the riser pipe buried in the water bed in the final position, a diver may retighten the frictional connection to lock the male cones to the monorail. Additional means may be provided for universally adjusting the connection so as to cure minor misalignments after the riser is in a final position. The relationship of the male and female cone members may be reversed so that the female cone is slidably mounted on the monorail of the riser pipe and the male cone is mounted on the platform. In this last configuration, it may be preferable to mount the mating cone members so they extend in an upwardly direction.

United States Patent [1 1 Plake [54] CONICAL STABBING GUIDE AND CLAMPSYSTEM FOR RISER PIPE INSTALLATION [75] Inventor: William Edgar Plake,Beaumont,

Tex.

I [73] Assignee: Brown & Root, Inc., Houston, Tex.

221 Filed: Sept. 29, 1971 211 Appl.No.: 184,692

Primary Examiner-Jacob Shapiro Attorney-James E. Cockfield 57 ABSTRACTAn apparatus and method are herein provided for installing a riser pipeon an offshore platform. A pluralityof vertically aligned female conemembers may be clamped along the length of the platform. A monorail maybe secured to the riser pipe and aligned along the 1 June 19, 1973 axisthereof. Mating male cone members may be slidably mounted on themonorail of the riser and roughly positioned for insertion into thefemale cones. A guide line may be fun from a surface winch through adead man ring or sheave mounted on the platform beneath a female conemember and up through the cone member to connect with the lower end ofthe mating male cone member. The riser pipe may be supported by asurface crane and disposed with the lower end of each male conepositioned generally above a female cone. The riser pipe is lowered sothat the male cones are partially inserted within the female cones. Inthis step, the guide line may be utilized as a positive control means ofbringing the cones into alignment for proper mating engagement. Afterthe cones are properly engaged, locking pins may be inserted through thelower portions of the male cones anda frictional connection between eachmale cone and the monorail released to slide the riser pipe downwardlyto its final position. The riser pipe may be jetted into the water bedin the conventional manner. With the riser pipe buried in the water bedin the final position, a diver may retighten the frictional connectionto lock the male cones to the monorail. Additional means may be providedfor universally adjusting the connection so as to cure minormisalignments after the riser is in a final position. The relationshipof the male and female cone members may be reversed so that the femalecone is slidably mounted on the monorail of the riser pipe and the malecone is mounted on the platform. In this Ilast configuration, it may bepreferable to mount the mating cone members so they extend in anupwardly direction.

29 Claims, 9 Drawing Figures PAIENIEB JUN 1 s 1915 SHEET 1 OF 4 PATENTEUJUN I 9 I973 SHEET 3 BF 4 CONICAL STABBING GUIDE AND CLAMP SYSTEM FORRISER PIPE INSTALLATION BACKGROUND OF THE INVENTION The inventionrelates to an apparatus and method for installing riser pipes tooffshore platforms and more specifically relates to an apparatus andmethod for guiding a riser pipe into a mounting position adjacent anoffshore platform and also for clamping the pipe thereto in oneoperation, using the same apparatus for both functions.

During the past few years, increased oil and gas exploratory activityhas occurred at substantial distances from shore lines in bodies ofwater such as the Gulf of Mexico. Such increased oil and gas exploratoryactivity and the consequent discovery of producing oil and gas havenecessitated many improvements in bringing the produced oil and gas tothe shore in an economical, safe, and practical manner. One of the mostdesirable methods for transporting gas and oil produced from offshorewells is through pipelines systems which connect an offshore wellhead tosuitable shore facilities.

A satisfactory arrangement for coupling a pipeline to a producing wellhas been found to be through a riser pipe or vertical tubular structurecoupled, at one end, to a pipeline which is laid on the bed of a body ofwater and, at the other end, to related apparatus on the platformstructure adjacent the wellhead. In past practice, the installation andcoupling of riser installations from each well to the pipeline hasproven to be a cumbersome, expensive, and sometimes dangerous task. Theuse of divers has been found necessary to install the risers and, sincethe depth of the water in which producing wells are being developed hasincreased over the years, the use of divers has been substantiallyadversely affected due to various physical limitations imposed by waterdepths of greater than 175 or 200 feet. In water depths in the vicintiyof 200 feet and deeper, a diver is incapable, without expensiveprocedures being employed, of staying down except for very short periodsto time and, therefore, the number of divers required per job hasconsiderably raised the cost of riser installation operations.

It would therefore be a significant advancement in the art if means andmethod. could be provided for shortening the period of time required forsafe installation of a riser pipe on an offshore platform. Similarly, ifthe number of diver man hours required for installing such a riser pipecould be reduced, a substantial reduction in cost and human exposure todanger could be provided.

OBJECTS AND SUMMARY OF THE PRESENT INVENTION It is therefore an objectof the present invention to rovide a new and improved means and methodfor installing riser pipes on offshore platforms wherein many of theproblems encountered in using existing equip ment are obviated. I

It is another object of the present invention to provide a new andimproved means and method for installing a vertical tubular structureadajcent a platform disposed in a body of water.

It is anotherv object of the present invention to provide a means andmethod for installing a riser pipe on an offshore platform in aneconomical, safe, and effective manner.

It is still another object of the present invention to provide a meansand method for installing a riser pipe on an offshore platform utilizingfewer diver man hours than has heretofore been practical.

It is yet another object of the present invention to provide a means andmethod for installing a riser pipe on an offshore platform wherein theneed for supporting a riser pipe in a nearly final position while adiver sets riser mounting clamps is eliminated.

It is a further object of the present invention to provide a means andmethod for installing a riser pipe on an offshore platform wherein eachstep during the installation operation may be positively controlled fromthe surface of the body of water.

It is yet a further object of the present invention to provide a meansand method for installing a riser pipe on an offshore platform whereinthe riser may be removed by simply removing a plurality of locking pinsfrom the clamping means and lifting the riser with sur' face craneequipment.

It is still a further object of the present invention to provide a meansand method for installing riser pipes on offshore platforms wherein thecurrently existing problem of fitting up and adjusting riser pipe clampsis minimized.

The objects of the present invention are carried out by the provision ofa means and methodfor securing a vertical tubular structure to aplatformsituated in a body of water wherein mating cone members areadjustably connected to the tubular structure and to the platform. Aguide line may be used to direct a male member of each mating pair ofcones into the female member and a locking pin may be inserted through aportion of the mating cones to secure the cones in an engaged position.A. monorail structure may be mounted on the tubular structure toslidingly guide the tubular structure into a final resting positionwhere it maybe connected with an underwater pipeline. Adjustment meansare associated with the mating cone pairs which maybe universallyadjusted while the tubular structure is mounted on the platform.

BRIEF DESCRIPTION OF THE DRAWINGS While the invention is particularlypointed out and distinctly claimed in the concluding portion of thespecification, a preferred embodiment is disclosed in the followingdetailed description which may best be understood when read inconnection with the accompanying drawings in which:

FIG. 1 is an elevation perspective view of the overall apparatus of thepresent invention; 7

FIG. 2 is an elevation perspective view of the apparatus shown in FIG. 1with a lowermost guiding .and clamping pair of cone members in partialengagement relationship;

FIG. 3 is a sequence perspective view of the apparatus shown in FIGS. 1and 2 showing all the included cone members in partial matingengagement;

FIG. 4 is a final sequence view of the apparatus shown in FIGS. 1, 2 and3 with all the included conical members in a final locked position andthe riser pipein a final position in the bed of a body of watersurrounding an offshore platform;

FIG. 5 is an elevation view of a female cone member anda ring clamped toanupright member of an offshore platform;

FIG. 6 is a partial sectional view of the'upright platform member andthe female cone member shown in FIG. 5 taken along line 6-6;

FIG. 7 is a partial elevation view of the feamle member and uprightplatform member shown in FIG. 6 in operational relationship with a riserpipe and a male cone member;

FIG. 8 is a sectional view of the riser pipe and the male cone member ofthe conical pair shown in FIG. 7 taken along line 8-8; and

FIG. 9 is an elevation view of the riser pipe and the male cone membershown in FIG. 7.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to thedrawings in which like numerals are used to indicate like partsthroughout the various views thereof, FIG. 1 shows a portion of anoffshore platform indicated generally as 10 and a riser pipe 12 beingbrought into position adjacent an upright member 14 of the offshoreplatform 10.

The offshore platform 10 includes a plurality of horizontally extendingsupport members 16 and associated diagonally extending members 18. Aplurality of female cones 20 are vertically aligned with and mounted onthe upright member 14 of the offshore platform 10. The cones are mountedby means of conventional clamps comprising a split collar 21 having acone supporting half 22 and a clamping half 24. The two halves 22 and 24may be secured by any conventional means such as a bolt and nutcombination extending through aligned holes defined in flanges which areformed in the halves 22 and 24 which will be described in detail inconnection with FIGS. 5-9. Cable stays 26 may be attached at one endthereof to each cone 20 and at the other end thereof to a second clamp28 mounted on a horizontally extending strut member 16. The stays 26provide stability and reinforcement to the connection between the cone20 and a supporting member of the platform.

The riser pipe 12 is encased in and grouted to an outer casing 30 whichextends axially along the riser pipe at least along the section of thepipe which will be directly connected with the offshore platform 10. Amonorail 32 is welded to the surface of the outer casing 30 of the riserpipe 12 and extends axially with respect thereto. Male cone members 34are slidably mounted on the monorail by means of a bracket-like basemember 36 which is configured to conform to the monorail. The detailedconstruction of the base member 36 supporting the male cone 34 will bedescribed in connection with FIGS. 6-9.

A guide line 38 is secured to the lowermost portion of each male coneand is run down through an associated female cone and out through anopen lower end thereof. The guide line is then run downwardly through acable pulling ring 40 and upwardly to a surface winch (not shown). Thecable pulling ring 40 is mounted on the upright member 14 of theoffshore platform 10 in a position vertically spaced beneath each femalecone and operates as a dead man for positively controlling, from thesurface, the movement of the male done 34.

Referring now to FIG. 2, it can be seen that the lowermost of the malecones 34 has been partially inserted within the lowermost of the femalecones 20. The riser is supported by means of a surface crane during theinsertion operation and the action of the guide line 38 is operable tobring the male cone 34 into engagement within female cone 20 with aminimum of assistance from a diver stationed adjacent the mountingapparatus. It will be noted, that the length of the male and femalecones, 34 and 20, increases from top to bottom so as to provide a moresubstantial support at the lowermost connection and to facilitateinstallation by providing a more pronounced clearance for the swingingof the male cones 34 into approximate alignment with the female cones 20for the final insertion and latching engagement thereof.

The operation shown in FIG. 2 may be conducted with the clamping devicesall comprising vertically mating cones or may be accomplished using avertically mating conical pair only as a bottom clamp and guide andutilizing conventional standard clamps along the remaining upwardportion of the installation.

FIG. 4 shows the apparatus of FIG. 3 wherein the vertically mating cones34 and 20 have been fully inserted and the riser pipe has been loweredto its final position. Positive positioning of the riser pipe isaccomplished after the cones have been lockingly engaged by looseningfrictional gripping means such as set screws or set bolts which may beused to lock the base member 36 of the male cone 34 with the monorail32. Upon loosening the set bolts (see FIGS. 7 and 8), the riser ispermitted to slide downwardly as the monorail 32 rides through thebracket-like base member 36 of each male cone. When the riser is in thefinal position shown in FIG. 4, the set bolts (not shown in FIG. 4) maybe retightened and any final minor adjustments may be made to relieveundesirable stresses. These adjustments may be made by loosening theclamp members 24 and 22 of the female cone and by rotating the femalecone about the upright member 14 or by moving the female and male conesvertically along the upright member 14 or the track monorail 32 'or byadjusting the standoff distance of the riser from the upright member 14by means of slidable members incorporated within the mounting structureof the vertical cone which slidable members will be discussed in detailwith respect to FIGS. 6-9. Of course, through bolts 97 could be insertedthrough slots 99 formed in either or both the base member of the malecone and the monorail as an alternative to the frictional lockingset-bolts. Similarly, through bolts 97 and set bolts could be used incombination wherein the set bolt would first be tightened and then thethrough bolts installed.

Referring now to FIG. 5, an elevation view of the female portion of themating cone arrangement is shown properly mounted on an upright member14 of an overall platform 10. It can be seen, the the female cone 20 issupportdd by means of horizontally extending web members 42. The webmembers 43 are, in turn, formed as a part of or welded to portion 22 ofthe overall clamping collar 21 used to secure the female cone 20 to theupright member 14. A plurality of nut and bolt combinations 44 areprovided and are operable to secure the two portions 22 and 24 of thefemale cone clamp together and in mounting engagement with the uprightmember 14. It is the nut and bolt combinations 44 which are loosened tovertically position or to rotatably arrange the female cone 20 withrespect to the remaining portions of the overall apparatus.

The cable pulling ring 40 is shown vertically spaced beneath the femalecone 20 and mounted on the upright member 14 in a manner substantiallysimilar to the mounting of the female cone 20. A collar-like clampingmember 46 is provided for mounting the ring member 40 on upright member14 and is formed with flanges 48 which define holes for the insertion ofbolt and nut combinations 50. The collar-like clamp member 46 for thecable pulling ring 40 may be adjusted vertically and rotatably about theupright member 14 in a manner similar to the adjustment of the femalecone 20. The cable pulling ring is provided with support struts 52 whichhave some vertical component for providing strength in the -verticalupward direction which is normal to the plane coincident with the ring40. The strut members 52 are effective for supporting the upwardlydirected forces acting on the ring by the action of the guide line 38when the male cone 34 is being pulled into mating engagement with thefemale cone 20. Of course, a sheave or pulley-like member could besubstituted for the ring 40. Eye members 54 may be pivotably connectedto one of the web members 42 supporting the female cone 20. The eyemembers 54 are used for connecting one end of a stay wire 26 with asimilar eye member 56 which is pivotally mounted in pad eye member 58which is rigidly formed as a part of a collar-like clamp member 60. Theeye member 56 is pivotable within the rigid eye member 58 so that an eyemember 62 connected at one end of the stay wire 26 and inserted throughthe pivotable eye member 56 of the clamp 60 is provided with universalmovement. A pivot pin 64 may be inserted through the rigid eye member 58and extended through the C- shaped ends of the pivotable eye member 56.The other end of the wire stay 26 terminates with an eye member 66 whichengages within the eye member 54 attached to the web portion 42 of thefemale cone supporting clamps 21. The eye member 54 mounted on thefemale cone clamp 21 may also be provided with a pivotable feature bymounting it with a pivot pin 68 extending through the C-shaped ends ofeye member 54 and through the mounting web portion 42 of the female conesupporting half 22 of the collar-like clamping mechanism 21.

Referring to FIG. 6, a partial sectional view of the apparatus of FIG. 5is shown wherein it becomes apparent that a funnel-shaped lip 70 isformed about the upper periphery of the female cone 20. The outward edge72 of the funnel 70 formed on the upper peripheral edge of the femalecone 20 is left open so as to facilitate the insertion of a male cone 34at which point of insertion the funnel 70 catches thd cone 34 and guidesit into a central hole 74 defined by the interior of the female cone 20.The lowermost portion 76 of the female cone 20 is open so that a malecone inserted therein will extend through the lowermost portion 76thereof.

As shown in FIG. 6, the stay wires 26 may be adjusted in length by meansof turnbuckles 78. Also, the clamping members 60 secured to one terminalend of the stay wire 26 may be moved horizontally along the member 16 byloosening nut-bolt combinations 80 and sliding the clamp 60 into adesired final position. The clamp 60 may be moved for rough adjustmentsand the turnbuckles may be used to tension the stay wire and make fineadjustments.

FIG. 7 shows the female cone 20 of FIGS. 5 and 6 with a male cone 34 andan attached riser pipe 12. It will be noted, that the guide line 38 issecured to one terminal end thereof to an eye member 82 attached to thelowermost end 84 of the male cone member 34.

The guide line 38 runs through the central opening 74 defined by thefemale cone and down through the cable pulling ring 40. The guide linethen runs upwardly to a surface winch (not shown).

The male cone member 34 is formed with a laterally extending bore hole86 formed through the lowermost end 84 thereof. When the male cone 34 isfully inserted within the female cone 20 a locking pin such as a cotterpin or the like is inserted into the bore hole 86 to prevent the conefrom being removed from within the female cone 20 due to wave action orviolent pressure variations in the riser pipe.

The base member 36 which supports the male cone 34 on the mono-rail 32is shown in FIGS. 7, 8 and 9 to comprise a bracketed C-shaped memberhaving two rows of longitudinally spaced threaded holes for insertion ofand threaded engagement with a plurality of set screw-like members 88.The monorail is shown to comprise a T-shape in cross sectionalconfiguration. The terminal ends 90 of the C-shaped base member 36engage under the laterally extending portions 92 of the T-shapedmonorail so as to slidingly secure the base member 36 to the monorail32.

Two vertically extending gusset plates 94 connect the C-shaped basemember 36 with a second C-shaped member 96. The C-shaped member 96 isarranged with the planar extension thereof perpendicular to the planarextension of the base member 36. The second C- shaped member 96 isformed with a plurality of threaded holes longitudinally spaced alongthe center thereof for the threaded engagement of set screw-like members98. The terminal ends 100 of the second C- shaped member 96 engage onthe under side 99 of a T shaped cross sectional extension 102 formed onthe upper portion 104 of the male cone 34. The cross sec tional T-shapedextension 102 is formed as a part of or is rigidly attached to the upperportion 104 of the male cone 34 which extension 102 rides within thespace defined by the C-shaped cross sectional area of the member 96 andmay be fixed with respect thereto by tightening several of the setbolt-like members 98 into pressure engagement with the T-shapedextension 102 through the C-shaped member 96. Once again through boltand slot arrangements could be substituted for the set bolt members 93or used in combination therewith.

It will be apparent from a perusal of the slidable nature of the basemember 36 and the T-shaped extension 102 of the male cone 34 that themale cone 34 may be moved vertically along the monorail or horizontallyalong the second C-shaped member 96 until an exact desired finalposition for the male member 34 has been reached. At that point, the setscrew-like members 88 and 98 associated with the C-shaped members 36 and96 may be tightened so as to rigidly fix the male cone 34 in the desiredposition.

BRIEF SUMMARY OF RISERPIPE INSTALLATION PROCEDURE As has been alreadynoted, it is only necessary to have one vertically mating cone pair topractice the present invention. When using only one such conecombination, it is preferred, although not necessary, that the cone pairbe positioned as the lowermost clamping member of a series of verticallyaligned clamping members for mounting the riser pipe adjacent theupright member of an offshore platform.

When installing a riser pipe in accordance with the present invention,the female cones are installed on the upright member 14 of the offshoreplatform and are roughly positioned for the insertion of male conesattached to the riser pipe. The cable stays 26 are secured to the femalecones at one terminal end and to either the horizontal support member 16or the diagonal support member 18 at the other terminal end thereof. Acable pulling ring 40 is installed vertically beneath each female cone20. The riser pipe is supported in the position adjacent the uprightmember of the platform by means of a surface crane. The cone guide line38 is thrdaded from the surface winch through the cable pulling ring 40,up through the female cone 20 and then secured to the pad eye 82 on thelower portin 84 of the male cone 34. While holding the riser pipe sothat the male cone 34 attached thereto will clear the tops of theassociated female cones 20, the male cone is pulled into the female coneguide by means of the guide line. The funnel portion 70 formed about theupper periphery of the female cone 20 assits in catching the lower end84 of the male cone 34. The riser pipe is then lowered until the malecone 34 and the female cone 20 are partially engaged. This coneengagement step is repeated for each male and female cone combinationused for the connection.

After the vertically mating cones have been axially aligned, all thecones are seated by relaxing the surfaced support and permittingthe malecones to forcibly engage within the female cones. Locking pins are theninserted in the latch holes 86 formed in the lower portion 84 of eachmale cone and the guide line 38 is removed. The set screws 88 betweenthe base portion 36 of the male cone and the monorail 32 are loosenedand the riser pipe is permitted to slide downwardly into a finalposition. Conventional pipe laying equipment may be used to jet away atrough in the mud bed to position the bottom portion of the risertherein. The riser pipe positioning operation is performed by theSliding of the monorail 32 through the C-shaped cross sectionalconfiguration of the base portion 36 of the male cone. After the riserpipe has settled into a final position, all the set screws 88 on thebase portion 36 are tightened so as to rigidly secure the riser pipe tothe male cone 34 which, in turn, is fully supported within the femalecone 20 and latched thereto by means of the locking pin 37.

After theriser pipe has been tightened in its final position, a divermay loosen the various set screws of the apparatus and universallyadjust the female cone member so as to relieve any unexpected stressesor dimensional misalignments.

SUMMARY OF THE ADVANTAGES OF THE INVENTION It can be seen that anapparatus and method have been herein provided for installing riserpipes on offshore platforms. The present invention obviates the need forsupporting the riser pipe in exact alignment, from the surface, while adiver tightens the clamps used to make the connection. The guide line 38and female cone funnel portion 70 make it possible to positively controlthe movement of the riser pipe into a properly aligned position and tostab each connection into a final connection merely with the used ofsurface power and with a minimum of diver effort. The monorail and thehorizontal and vertical adjustment features of the invention enable adiver to make dimensional adjustments without removing the riser fromthe connection. The mono-rail, which is ordinarly available only onplatforms originally provided with permanent monorail systems, providespositive control for lowering the riser pipe. A fixed position withrespect to the platform is then effected by the simple tightening of apluralty of set screws and installing of a latch pin. Riser pipe removalis similarly facilitated by simply removing the latching pins andlifting the riser by means of the surface crane.

Using the present invention, fewer divers are necessary to make thevarious connections and adjustments associated with the installation ofriser pipes. Also less time is required for positioning and mounting ariser pipe at an offshore platform site. The cumulative effect of allthe aforementioned advantages is that riser pipe installation operationsare now safer, less expensive and less cumbersome than heretoforepossible.

While what has been shown herein is a preferred embodiment of thepresent invention, it is of course understood that various modificationsand changes may be made herein without departing from the invention. Forexample, the position of the .male and female cone members may bereversed so that the female cone is mounted on the riser and the malecone is mounted on the platform. Also, if a monorail is already mountedon a platform, adjustable female cone members could be fitted withC-shaped bases and slidingly positioned on the monorail for engagementwith male cones on the riser pipe. It is therefore intended to cover inthe appended claims all such modifications and changes as may fallwithin the true spirit and scope of the present invention.

I claim:

1. In an apparatus for attaching a riser pipe to an offshore platformwherein the platform includes structural member means and a clamp meansfor securing the riser pipe to the structural member means theimprovement comprising:

the clamp means including at least,

a first pair of vertically alignable mating cone members, and

a second pair of vertically alignable mating cone members, said firstand second pair of mating cone members having variatn axial lengths,

rail mdans fixedly mounted on either said riser pipe or said offshoreplatform and slidably secured to one member of each of said at leastfirst and second pair of mating cone members;

whereby the riser pipe may be positioned next to the offshore platformby pivoting said riser pipe about the longer of said first and secondpair of mating cone members after partial mating engagement thereof.

2. An apparatus according to claim 1 with the addition of:

at least one guide line means attached at a first end thereof to one ofsaid mating cone members of at least one of said first and second matingcone members and passing through the other of said mating cone membersto a point adjacent the surface of said body of water at a second endthereof;

whereby said second end of said guide line means may be manipulated topositively control the engagement of said vertically alignable matingcones.

3. In an apparatus for attaching a riser pipe to an offshore platformwherein the platform includes structural member means and a clamp meansfor securing the riser pipeto the structural member means theimprovement comprising:

. the clamp means including at least one pair of verti cally alignablecone members;

rail meansfixedly mounted on the riser pipe and slidably secured to onemember of dach of said at least one pair of mating cone members;

a ring means secured to the structural member beneath said verticallyalignable mating cone members; and

guideline means attached at a first end thereof to' one of said matingcone members passing through the other of said mating cone members,passing through said ring means, and to a point adjacent the saidsurface of said I body of water at a second end thereof;

whereby the one of said mating cone members may be guided into anengagement with the other of said mating cone members in response to anupward pull on said guideline toward a second end thereof and wherebythe riser pipe may bedownwardl y guided to a position within the bed ofa body of water surrounding the offshore platform.-

4. An apparatus according to claim 3 with the addition of locking meansfor securing said at least one pair of vertically alignable mating conemembers in engagement with each other.

5. An apparatus according to claim 4 wherein said locking meanscomprises a locking pininserted through a bore hole formed'transverselythrough at leat one of said mating cone members.

6. Apparatus for attaching a riser to an offshore platform comprising:

'a casing coaxiallyisurrounding said riser pipe, secured tosaid riserpipe and extending longitudinally along at least a portion thereof,

rail means secured to said casing and extending longitudinally thereof;

clamp means including vertically alignable mating cone members one ofsaid cone members being slidably mounted on said rail means and theother of said cone members beingconnected to said offshore platform; a

locking means included-on said clamp means and op v erable to fixedlysecure said clamp means to said rail means; and 5 whereby said riserpipe may be slidably guided in the vertically downward direction bysupporting said clamp means in a fixed position and releasing saidlocking means.

7; Apparatus comprising:

male cone means;

I a generally C-shaped bracket base for supporting said cone means andextending generally longitudinally with respect to the longitudinalextension of said male cone means;

a second C-shaped bracket member rigidly secured to said C-shapedbracket base member;

said second generally C-shaped bracket member being generallyperpendicular to the planar extension of said generally C-shaped bracketbase member; f

a base portion of said male cone member being formed wtih a generallyT-shaped cross-sectional area;

said generally T-shaped cross-sectional base portion of said male conemember being slidably engageable within said generally C-shapedcross-sectional configuration of said second C-shaped bracket member;locking means provided on said second generally C- shaped bracket memberfor fixedly securingsaid male cone to said second generally C-shapedmember; whereby the position of thd axis of said male cone member may beadjusted with respectto the planar extension of said generally C-shapedbracket bas member. 8. An apparatus according to claim 7 with theaddition of pad eye means disposed at a free end of said male conemember.

9. An apparatus according to claim 8 wherein: said locking meansincludes set bolts threadedly engaged through said second generally'C-shaped bracket member and engagealble with a surface of saidgenerally T-shaped cross-sectional base portion of said male cone; iwherein said locking means further includes through bolts insertedthrough slots formed in said O shaped bracket member and said T-shapedbase portion; and

whereby said set bolts may be tightened to hold associated coneapparatus in a fixedposition for the insertion and tightening of saidthrough bolts in said slots. v i 10. Apparatus comprising: female conemeans; said female cone means being generally hollow and open at theaxial ends thereof; funnel means disposed about a first axial end ofsaid female cone me'ans;" a a portion of said funnel means being cutaway to form an axial slot for the radial insertion of a male conemember into the area defined by said, funnel means; Y a y 1 clamp meansfor securing said cone means to a structural member of an offshoreplatform;

said clamp means being slidable longitudinally of said extension of saidstructural member means; whereby said female cone means may bepositioned at any desired point along the longitudinal extension of saidstructural member means. 11. Apparatus comprising: an upright structuralmember on an offshore platform; r ring means adjustably mounted on saidupright structural member; i hollow fer'nale cone means adjustablymounted 'on said upright member above said ring means; stay line meanssecured to said female cone means at a first end of said stay line meansand'secured to another structural member of saidoffshore platform at asecond end of said stay line means; said stay line means connected withsaid female cone means by a universally movable connector means;

means at a desired position along the longitudinal the second end ofsaid stay line means attached to said other structural member is securedthereto by means of a universally movable connector means; and

adjustment means is provided along the length of said stay line meansfor tensioning said stay line in response to rotation of said adjustmentmeans.

12. Apparatus for coupling a first elongated member to a secondelongated member comprising:

at least two longitudinally alignable male connector means havingvariant axial lengths mounted on said first elongatdd member;

at least two longitudinally alignable female connector means havingvariant axial lengths mounted on said second elongated member;

said at least two female connector means operable for sequentiallyreceiving said at least two male connector means to form a couplingmeans;

said at least two female connector means having axial lengths compatiblewith associated male connector means;

rail means secured to said first elongated member and extendinglongitudinally thereof; and

said rail means being slidably mounted through a portion of saidcoupling means and operable to guide relative longitudinal movementbetween first and second elongated members.

13. Apparatus for coupling a first elongated member to a secondelongated member comprising:

longitudinally alignable male connector means mounted on said firstelongated member;

longitudinally alignable female connector means' mounted on said secondelongated member;

said female connector means operable for receiving said male connectormeans to form a coupling means;

rail means secured to said first elongated member and extendinglongitudinally thereof;

said rail means being slidably mounted through a portion of saidcoupling means and operable to guide relative longitudinal movementbetween said first and said second elongated members;

said second elongated member comprising an upright structural member ofan offshore platform disposed within a body of water;

guide line means attached at a first end thereof to said male connectormeans and passing through said female connector to a point adjacent thesurface of the body of water at a second end thereof; and

said guide line means being operable to guide said male cone means intoengagement relationship with said female cone means in response to themovement of said guide line means at the second end thereof.

14. Apparatus for coupling a first elongated member to a secondelongated member comprising:

longitudinally alignable male connector means mounted on said firstelongated member;

longitudinally alignable female connector means mounted on said secondelongated member;

said female connector means operable for receiving said male connectormeans to form a coupling means; 1

rail means secured to said first elongated member and extendinglongitudinally thereof;

said rail means being slidably mounted to a portion of said couplingmeans and operable to guide relative longitudinal movement between saidfirst and said second elongated members; and

locking means removably app'liable to said coupling means for securingsaid male connector means and said female connector means againstrelative longitudinal movement therebetween after the engagementthereof.

15. An apparatus according to claim 14 with the addition of ring meansdisposed beneath said female connector means;

said guide line means passing from said male cone means generallydownwardly through said female connector means and through said rngmeans to extend upwardly to a point above the surface of said body ofwater; and

said ring means operable to provide a downward force to said male conemeans in-responseto an upward force applied to said guide line meanstoward said second end thereof.

16. Apparatus for coupling a first elongated member to a secondelongated member comprising:

longitudinally alignable male connector means mounted on said firstelongated member; longitudinally alignable female connector meansmounted on said second elongated member;

said female connector means operable for receiving said male connectormeans to form a coupling means;

rail means secured to said first elongated member and extendinglongitudinally thereof;

said rail means being slidably mounted through a portion of saidcoupling means and operable to guide relative longitudinal movementbetween said first and said second elongated members; and adjustmentmeans on said coupling means for adjust- 1 ing the stand-off distancebetween said first and second elongated members in a directiontransverse to the longitudinal extension thereof.

17. Apparatus for coupling a first elongated member to a secondelongated member comprising:

longitudinally alignable male connector means mounted on said firstelongated member; longitudinally alignable female connector meansmounted on said second elongated member; said female connector meansoperable for receiving said male connector means to form a couplingmeans;

rail means secured to said first elongated member and extendinglongitudinally thereof;

said rail means being slidably mounted to a portion of said couplingmeans and operable to guide relative longitudinal movement between saidfirst and said second elongated members;

said male connector means comprises said portion of said coupling meansslidably mounted on said rail means; and

locking means is provided on said male connector means for releasablyfixing the position of said male connector means on said rail means.

18. An apparatus according to claim 17 wherein said rail means comprisesa monorail secured to said first 5 elongated member; and

said male connector means is slidably connected to said monorail meansby a bracket base member being C-shaped in cross-sectionalconfiguration.

19. An apparatus according to claim 17 wherein said locking meanscomprises set bolt means threadedly mounted through said bracket basemember and engageable with a surface on said monorail and furtherincludes through bolt means operably extending through slots formed insaid male connector means and said rail means.

20. An'apparatus for mounting a riser pipe on an offshore platformcomprising:

at least two generally vertically alignable male connector members ofdifferent axial length mounted on one of said riser pipes and saidoffshore platform; at least two generally vertically alignable femaleconnector means of different axial length mounted on the other side ofsaid riser pipe and said offshore platform; said at least two femaleconnector means operable for sequentially receiving said at least twomale connector means to form a coupling means; said at least two femaleconnector means having axial lengths compatible with associated maleconnector means; rail means mounted on said riser pipe and axiallyaligned therewith; and said rail means slidably mounted within a portionof said coupling means and operable to guide the generally verticalmovement of said riser pipe with re spect to said offshore platform. 21.An apparatus according to claim 20: wherein each of said male connectormeans comprisesa solid frustoconical shaped member; each of said femaleconnector means comprises a hollow frustoconical shaped member; andwherein the shape of the internal surface of each said hollow femaleconnector means corresponds with the outside'surface of each said solidmale frustoconical shaped member. 22. An apparatus for mounting a riserpipe on an offshore platform comprising: Y

generally vertically alignable male connector means mounted on one'ofsaid riser pipes on said offshore platform; said made connector meanscomprises a solid frustoconical shaped member; generaly verticallyalignable female connector means mounted on the other of said riser pipeon said offshore platform; said female connector means comprising ahollow frustoconical shaped member; said female connector means operablefor receiving said male connector means to form a coupling means;wherein the shape of the internal surface of said hollow femaleconnector means corresponds with the outside surface of said solid malefrustoconical member; rail means mounted on said riser pipe and axiallyaligned therewith; said rail means slidably mounted within a portion ofsaid coupling means and operable to guide a generally vertical movementof said riser pipe with respect'to said offshore platform; ring meanssecured to said platform beneath said female connector means; guide linemeans secured at one end to a lower portion of said male connectormeans; and

said guide line means passing from said male connector means axiallythrough said female connector means and downwardly through said ringmeans thereafter to extend upwardly toward the surface of said body ofwater;

whereby the upward movement of said guide line means is operable toprovide theinsertable engagement of said male member within said femalemember from a position above the surface of said body of water. i 23.Apparatus according to claim 22: with the addition of adjustment meansfor adjusting the generally vertical position of said male member andsaid female memberwith respect to said riser pipe and said offshoreplatform; and adjustment means provided adjacent said male cone meansfor adjusting the stand-off distance between said platform member andsaid riser pipe after the engagement of said male cone member withinsaid female cone member. 24. A method for installing and clamping ariser pipe to an offshore platform comprising the steps:

installing a hollow frusto-conical shaped female connector member on theoffshore platform; installing a cable pulling ring on the offshoreplatform in a position beneath said frusto-conical female connectormember; providing a longitudinally extending rail means on the riserpipe; slidably attaching a frusto-conlically shaped male member to saidrail means on the riser pipe;

providing set bolts for f xing the position of said male member on saidrail means;

threading a guide line from a free end of the male connector downwardlythrough the female connector and downwardly through the pulling ring andthereafterdirecting the guide line upwardly to a point above the surfaceof a body of water surrounding the offshore platform; g

attaching the second end of said guide line to a surface winch;

supporting the riser pipe adjacent the offshore platform with the malecone members disposed generally above the mating female cone members;

while 'supportiong the riser pipe so the narrow axial end of the malecone will clear the wide axial. end of the female cone, pulling the malecone into the female cone by pulling upwardly on the guide line;

lowering the riser pipe until the mating cones are slightly engaged;

pulling on the guide line while lowering the riser so asto' guide themale cone into the female cone;

seating all the male cones within the female cones by relaxing thesurface support of the riser pipe;

installing locking pins 20. as to hold the male cones and female conesin engagement;

removing theguideline;

loosening said set screws which. fixedly secure the male cone to theriser monorail;

whereby the riser pipe slides downwardly into the bed of the body ofwater as the monorail slides through the slidable "connection between vthe monerail and the male cone member;

tightening the set bolts associated with the male member whereby themale member becomes fixed with respect mine riser pipe; and

installing through bolts through slots formed in said cone members andsaid monorail to reinforce the holding capability of said set bolts. 25.A method for installing a riser pipe on an offshore platform comprisingthe steps:

providing female cone members on the offshore platform; providing malecone members on the riser pipe; the male cone members being slidablysecured to the riser pipe; inserting the male cone members within thefemale cone members to form a coupling; releasing the releasableconnection between the male cone members and the riser pipe whereby theriser pipe may be slidably guided downwardly into a final position underthe influence of gravity; tightening the connection between the malecone member and the riser pipe member thereafter. 26. A method accordingto claim with the additional step of attaching stay lines from thefemale cone members to platform structural members. I

27. A method for installing a riser pipe upon an offshore platformcomprising the steps:

providing female cone members on the offshore plat- 'form; providingmale cone members on the riser pipe; the male cone members beingslidably secured to the riser pipe; inserting the male cone memberswithin the female cone members to form a coupling; 1 releasing thereleasable connection between the male cone members to form a coupling;releasing the releasable connection between the male cone member and theriser pipe to guide the riser pipe downwardly into a final positionunder the influence of gravity; tightening the connection between themale cone member and the riser pipe member thereafter; providingadjustment means for varying distance between the longitudinal extensionof the male cone member and the axis of the riser pipe; and adjustingthe stand-off distance between the riser pipe and the offshore platformafter the riser pipe has been lowered into a rough final position in thebed of the body of water.

28. A method for installing a riser pipe upon an offshore platformcomprising the steps:

providing female cone members on the offshore platform; providing malecone members on the riser pipe;

the male cone members being slidably secuted to the reiser pipe;

inserting the male cone members within the female cone members to form acoupling;

releasing the releasable connection between the male cone members andthe riser pipe to guide the riser pipe downwardly into a inal positionunder the influence of gravity;

tightening the connection between the male cone member and the riserpipe therafter;

providing a guide line extending from each male cone member downwardlythrough each female cone member and upwardly to a point adjacent the surface of a body of water surrounding the offshore platform; and

wherein the step of inserting the male cone members within the femalecone members to form a coupling includes a step of applying an upwardforce on the guide line.

29. In an offshore structure, including a platform and verticallyextending rail means mounted on said platform, the addition of:

at least two female conemeans having different variant lengths;

each of said female cone means being slidably mounted on said railmeans;

said female cone means arranged in order of increasing axial length;means for locking each of said female cone means in a fixed position onsaid rail means;

at least one of said female cone means being adjsutable in a directiontransverse to the longitudinal extension of said rail means; and

each of said female cone means being operable to receive correspondingmale cone means having different axial lengths provided on a riser pipeto be mounted on said offshore platform.

1. In an apparatus for attaching a riser pipe to an offshore platformwherein the platform includes structural member means and a clamp meansfor securing the riser pipe to the structural member means theimprovement comprising: the clamp means including at least, a first pairof vertically alignable mating cone members, and a second pair ofvertically alignable mating cone members, said first and second pair ofmating cone members having variatn axial lengths, rail mdans fixedlymounted on either said riser pipe or said offshore platform and slidablysecured to one member of each of said at least first and second pair ofmating cone members; whereby the riser pipe may be positioned next tothe offshore platform by pivoting said riser pipe about the longer ofsaid first and second pair of mating cone members after partial matingengagement thereof.
 2. An apparatus according to claim 1 with theaddition of: at least one guide line means attached at a first endthereof to one of said mating cone members of at least one of said firstand second mating cone members and passing through the other of saidmating cone members to a point adjacent the surface of said body ofwater at a second end thereof; whereby said second end of said guideline means may be manipulated to positively control the engagement ofsaid vertically alignable mating cones.
 3. In an apparatus for attachinga riser pipe to an offshore platform wherein the platform includesstructural member means and a clamp means for securing the riser pipe tothe structural member means the improvement comprising: the clamp meansincluding at least one pair of vertically alignable cone members; railmeans fixedly mounted on the riser pipe and slidably secured to onemember of dach of said at least one pair of mating cone members; a ringmeans secured to the structural member beneath said vertically alignablemating cone members; and guideline means attached at a first end thereofto one of said mating cone members passing through the other of saidmating cone members, passing through said ring means, and to a pointadjacent the said surface of said body of water at a second end thereof;whereby the one of said mating cone members may be guided into anengagement with the other of said mating cone members in response to anupward pull on said guideline toward a second end thereof and wherebythe riser pipe may be downwardly guided to a position within the bed ofa body of water surrounding the offshore platform.
 4. An apparatusaccording to claim 3 with the addition of locking means for securingsaid at least one pair of vertically alignable mating cone members inengagement with each other.
 5. An apparatus according to claim 4 whereinsaid locking means comprises a locking pin inserted through a bore holeformed transversely through at leat one of said mating cone members. 6.Apparatus for attaching a riser to an offshore platform comprising: acasing coaxially surrounding said riser pipe, secured to said riser pipeand extending longitudinally along at least a portion thereof, railmeans secured to said casing and extending longitudinally thereof; clampmeans including vertically alignable mating cone members one of saidcone members being slidably mounted on said rail means and the other ofsaid cone members being connected to said offshore platform; lockingmeans included on said clamp means and operable to fixedly secure saidclamp means to said rail means; and whereby said riser pipe may beslidably guided in the vertically downward direction by supporting saidclamp means in a fixed position and releasing said locking means. 7.Apparatus comprising: male cone means; a generally C-shaped bracket basefor supporting said cone means and extending generally longitudinallywith respect to the longitudinal extension of said male cone means; asecond C-shaped bracket member rigidly secured to said C-shaped bracketbase member; said second generally C-shaped bracket member beinggenerally perpendicular to the planar extension of said generallyC-shaped bracket base member; a base portion of said male cone memberbeing formed wtih a generally T-shaped cross-sectional area; saidgenerally T-shaped cross-sectional base portion of said male cone memberbeing slidably engageable within said generally C-shaped cross-sectionalconfiguration of said second C-shaped bracket member; locking meansprovided on said second generally C-shaped bracket member for fixedlysecuring said male cone to said second generally C-shaped member;whereby the position of thd axis of said male cone member may beadjusted with respect to the planar extension of said generally C-shapedbracket base member.
 8. An apparatus according to claim 7 with theaddition of pad eye means disposed at a free end of said male conemember.
 9. An apparatus according to claim 8 wherein: said locking meansincludes set bolts threadedly engaged through said second generallyC-shaped bracket member and engageable with a surface of said generallyT-shaped cross-sectional base portion of said male cone; wherein saidlocking means further includes through bolts inserted through slotsformed in said C-shaped bracket member and said T-shaped base portion;and whereby said set bolts may be tightened to hold associated coneapparatus in a fixed position for the insertion and tightening of saidthrough bolts in said slots.
 10. Apparatus comprising: female conemeans; said female cone means being generally hollow and open at theaxial ends thereof; funnel means disposed about a first axial end ofsaid female cone means; a portion of said funnel means being cut away toform an axial slot for the radial insertion of a male cone member intothe area defined by said funnel means; clamp means for securing saidcone means to a structural member of an offshore platform; said clampmeans being slidable longitudinally of said structural member means;tightening means for fixedly securing said clamp means at a desiredposition along the longitudinal extension of said structural membermeans; whereby said female cone means may be positioned at any desiredpoint along the longitudinal extension of said structural member means.11. Apparatus comprising: an upright structural member on an offshoreplatform; ring means adjustably mounted on said upright structuralmember; hollow female cone means adjustably mounted on said uprightmember above said ring means; stay line means secured to said femalecone means at a first end of said stay line means and secured to anotherstructural member of said offshore platform at a second end of said stayline means; said stay line means connected with said female cone meansby a universally movable connector means; the second end of said stayline means attached to said other structural member is secured theretoby means of a universally movable connector means; and adjustment meansis provided along the length of said stay line means for tensioning saidstay line in response to rotation of said adjustment means. 12.Apparatus for coupling a first elongated member to a second elongatedmember comprising: at least two longitudinally alignable male connectormeans having variant axial lengths mounted on said first elongatddmember; at least two longitudinally alignable female connector meanshaving variant axial lengths mounted on said second elongated member;said at least two female connector means operable for sequentiallyreceiving said at least two male connector means to form a couplingmeans; said at least two female connector means having axial lengthscompatible with associated male connector means; rail means secured tosaid first elongated member and extending longitudinally thereof; andsaid rail means being slidably mounted through a portion of saidcoupling means and operable to guide relative longitudinal movementbetween first and second elongated members.
 13. Apparatus for coupling afirst elongated member to a second elongated member comprising:longitudinally alignable male connector means mountEd on said firstelongated member; longitudinally alignable female connector meansmounted on said second elongated member; said female connector meansoperable for receiving said male connector means to form a couplingmeans; rail means secured to said first elongated member and extendinglongitudinally thereof; said rail means being slidably mounted through aportion of said coupling means and operable to guide relativelongitudinal movement between said first and said second elongatedmembers; said second elongated member comprising an upright structuralmember of an offshore platform disposed within a body of water; guideline means attached at a first end thereof to said male connector meansand passing through said female connector to a point adjacent thesurface of the body of water at a second end thereof; and said guideline means being operable to guide said male cone means into engagementrelationship with said female cone means in response to the movement ofsaid guide line means at the second end thereof.
 14. Apparatus forcoupling a first elongated member to a second elongated membercomprising: longitudinally alignable male connector means mounted onsaid first elongated member; longitudinally alignable female connectormeans mounted on said second elongated member; said female connectormeans operable for receiving said male connector means to form acoupling means; rail means secured to said first elongated member andextending longitudinally thereof; said rail means being slidably mountedto a portion of said coupling means and operable to guide relativelongitudinal movement between said first and said second elongatedmembers; and locking means removably appliable to said coupling meansfor securing said male connector means and said female connector meansagainst relative longitudinal movement therebetween after the engagementthereof.
 15. An apparatus according to claim 14 with the addition ofring means disposed beneath said female connector means; said guide linemeans passing from said male cone means generally downwardly throughsaid female connector means and through said rng means to extendupwardly to a point above the surface of said body of water; and saidring means operable to provide a downward force to said male cone meansin response to an upward force applied to said guide line means towardsaid second end thereof.
 16. Apparatus for coupling a first elongatedmember to a second elongated member comprising: longitudinally alignablemale connector means mounted on said first elongated member;longitudinally alignable female connector means mounted on said secondelongated member; said female connector means operable for receivingsaid male connector means to form a coupling means; rail means securedto said first elongated member and extending longitudinally thereof;said rail means being slidably mounted through a portion of saidcoupling means and operable to guide relative longitudinal movementbetween said first and said second elongated members; and adjustmentmeans on said coupling means for adjusting the stand-off distancebetween said first and second elongated members in a directiontransverse to the longitudinal extension thereof.
 17. Apparatus forcoupling a first elongated member to a second elongated membercomprising: longitudinally alignable male connector means mounted onsaid first elongated member; longitudinally alignable female connectormeans mounted on said second elongated member; said female connectormeans operable for receiving said male connector means to form acoupling means; rail means secured to said first elongated member andextending longitudinally thereof; said rail means being slidably mountedto a portion of said coupling means and operable to guide relativelongitudinal movement between said first and said second elongatedmembers; said male connector Means comprises said portion of saidcoupling means slidably mounted on said rail means; and locking means isprovided on said male connector means for releasably fixing the positionof said male connector means on said rail means.
 18. An apparatusaccording to claim 17 wherein said rail means comprises a monorailsecured to said first elongated member; and said male connector means isslidably connected to said monorail means by a bracket base member beingC-shaped in cross-sectional configuration.
 19. An apparatus according toclaim 17 wherein said locking means comprises set bolt means threadedlymounted through said bracket base member and engageable with a surfaceon said monorail and further includes through bolt means operablyextending through slots formed in said male connector means and saidrail means.
 20. An apparatus for mounting a riser pipe on an offshoreplatform comprising: at least two generally vertically alignable maleconnector members of different axial length mounted on one of said riserpipes and said offshore platform; at least two generally verticallyalignable female connector means of different axial length mounted onthe other side of said riser pipe and said offshore platform; said atleast two female connector means operable for sequentially receivingsaid at least two male connector means to form a coupling means; said atleast two female connector means having axial lengths compatible withassociated male connector means; rail means mounted on said riser pipeand axially aligned therewith; and said rail means slidably mountedwithin a portion of said coupling means and operable to guide thegenerally vertical movement of said riser pipe with respect to saidoffshore platform.
 21. An apparatus according to claim 20: wherein eachof said male connector means comprises a solid frustoconical shapedmember; each of said female connector means comprises a hollowfrustoconical shaped member; and wherein the shape of the internalsurface of each said hollow female connector means corresponds with theoutside surface of each said solid male frustoconical shaped member. 22.An apparatus for mounting a riser pipe on an offshore platformcomprising: generally vertically alignable male connector means mountedon one of said riser pipes on said offshore platform; said madeconnector means comprises a solid frustoconical shaped member; generalyvertically alignable female connector means mounted on the other of saidriser pipe on said offshore platform; said female connector meanscomprising a hollow frustoconical shaped member; said female connectormeans operable for receiving said male connector means to form acoupling means; wherein the shape of the internal surface of said hollowfemale connector means corresponds with the outside surface of saidsolid male frustoconical member; rail means mounted on said riser pipeand axially aligned therewith; said rail means slidably mounted within aportion of said coupling means and operable to guide a generallyvertical movement of said riser pipe with respect to said offshoreplatform; ring means secured to said platform beneath said femaleconnector means; guide line means secured at one end to a lower portionof said male connector means; and said guide line means passing fromsaid male connector means axially through said female connector meansand downwardly through said ring means thereafter to extend upwardlytoward the surface of said body of water; whereby the upward movement ofsaid guide line means is operable to provide the insertable engagementof said male member within said female member from a position above thesurface of said body of water.
 23. Apparatus according to claim 22: withthe addition of adjustment means for adjusting the generally verticalposition of said male member and said female member with respect to saidriser Pipe and said offshore platform; and adjustment means providedadjacent said male cone means for adjusting the stand-off distancebetween said platform member and said riser pipe after the engagement ofsaid male cone member within said female cone member.
 24. A method forinstalling and clamping a riser pipe to an offshore platform comprisingthe steps: installing a hollow frusto-conical shaped female connectormember on the offshore platform; installing a cable pulling ring on theoffshore platform in a position beneath said frusto-conical femaleconnector member; providing a longitudinally extending rail means on theriser pipe; slidably attaching a frusto-conically shaped male member tosaid rail means on the riser pipe; providing set bolts for fixing theposition of said male member on said rail means; threading a guide linefrom a free end of the male connector downwardly through the femaleconnector and downwardly through the pulling ring and thereafterdirecting the guide line upwardly to a point above the surface of a bodyof water surrounding the offshore platform; attaching the second end ofsaid guide line to a surface winch; supporting the riser pipe adjacentthe offshore platform with the male cone members disposed generallyabove the mating female cone members; while supportiong the riser pipeso the narrow axial end of the male cone will clear the wide axial endof the female cone, pulling the male cone into the female cone bypulling upwardly on the guide line; lowering the riser pipe until themating cones are slightly engaged; pulling on the guide line whilelowering the riser so as to guide the male cone into the female cone;seating all the male cones within the female cones by relaxing thesurface support of the riser pipe; installing locking pins 20 as to holdthe male cones and female cones in engagement; removing the guide line;loosening said set screws which fixedly secure the male cone to theriser monorail; whereby the riser pipe slides downwardly into the bed ofthe body of water as the monorail slides through the slidable connectionbetween the monorail and the male cone member; tightening the set boltsassociated with the male member whereby the male member becomes fixedwith respect to the riser pipe; and installing through bolts throughslots formed in said cone members and said monorail to reinforce theholding capability of said set bolts.
 25. A method for installing ariser pipe on an offshore platform comprising the steps: providingfemale cone members on the offshore platform; providing male conemembers on the riser pipe; the male cone members being slidably securedto the riser pipe; inserting the male cone members within the femalecone members to form a coupling; releasing the releasable connectionbetween the male cone members and the riser pipe whereby the riser pipemay be slidably guided downwardly into a final position under theinfluence of gravity; tightening the connection between the male conemember and the riser pipe member thereafter.
 26. A method according toclaim 25 with the additional step of attaching stay lines from thefemale cone members to platform structural members.
 27. A method forinstalling a riser pipe upon an offshore platform comprising the steps:providing female cone members on the offshore platform; providing malecone members on the riser pipe; the male cone members being slidablysecured to the riser pipe; inserting the male cone members within thefemale cone members to form a coupling; releasing the releasableconnection between the male cone members to form a coupling; releasingthe releasable connection between the male cone member and the riserpipe to guide the riser pipe downwardly into a final position under theinfluence of gravity; tightening the connection between the male conemember and the riser pipe meMber thereafter; providing adjustment meansfor varying distance between the longitudinal extension of the male conemember and the axis of the riser pipe; and adjusting the stand-offdistance between the riser pipe and the offshore platform after theriser pipe has been lowered into a rough final position in the bed ofthe body of water.
 28. A method for installing a riser pipe upon anoffshore platform comprising the steps: providing female cone members onthe offshore platform; providing male cone members on the riser pipe;the male cone members being slidably secuted to the reiser pipe;inserting the male cone members within the female cone members to form acoupling; releasing the releasable connection between the male conemembers and the riser pipe to guide the riser pipe downwardly into ainal position under the influence of gravity; tightening the connectionbetween the male cone member and the riser pipe therafter; providing aguide line extending from each male cone member downwardly through eachfemale cone member and upwardly to a point adjacent the surface of abody of water surrounding the offshore platform; and wherein the step ofinserting the male cone members within the female cone members to form acoupling includes a step of applying an upward force on the guide line.29. In an offshore structure, including a platform and verticallyextending rail means mounted on said platform, the addition of: at leasttwo female cone means having different variant lengths; each of saidfemale cone means being slidably mounted on said rail means; said femalecone means arranged in order of increasing axial length; means forlocking each of said female cone means in a fixed position on said railmeans; at least one of said female cone means being adjsutable in adirection transverse to the longitudinal extension of said rail means;and each of said female cone means being operable to receivecorresponding male cone means having different axial lengths provided ona riser pipe to be mounted on said offshore platform.